As is known, vehicle seats comprise a seat back portion and a seat bottom portion, and are typically configured for adjustment to accommodate a seat occupant's particular dimensions. The entire seat structure can be translated in a vehicle fore-and-aft direction to accommodate the seat occupant's leg and arm length. Likewise, the seat back portion may be tilted in a vehicle fore and aft direction according to user preference. Still more, vehicle seats are typically provided with a mechanism for adjusting a height of the vehicle seat to accommodate the seat occupant's leg length. Such mechanisms may be provided as motorized or manual systems.
Manual seat height adjustment mechanisms, while advantageous in terms of cost of manufacture and lesser complexity compared to motorized systems, disadvantageously often require increased user effort to operate. Commonly, lever-driven mechanisms are used to attempt to reduce the user effort needed to raise or lower a seat to a desired height. Levers, while substantially effective for their intended purpose, require additional packaging considerations relating to needed space for the lever to be positioned, accessed, and actuated, and may be difficult for a user to find.
To solve these and other problems, the present disclosure describes a manual seat height adjustment actuator mechanism comprising an epicycloid gear transmission having eccentric gearing. Advantageously, the described mechanism reduces the user effort necessary to provide sufficient torque to drive the mechanism, thus reducing user fatigue and improving user comfort and satisfaction.